First-principles Approaches to Simulate Lithiation in Silicon Electrodes Qianfan Zhang1,2, Yi Cui2,3 and Enge Wang4* 1 School of Material Science and Engineering, Beihang University, Beijing 100191, China 2 Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA. 3 Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA. 4 School of Physics, Peking University, Beijing 100871, China *Corresponding author, email:
[email protected] Abstract Silicon is viewed as an excellent electrode material for lithium batteries due to its high lithium storage capacity. Various Si nano-structures, such as Si nanowires, have performed well as lithium battery anodes and have opened up exciting opportunities for the use of Si in energy storage devices. The mechanism of lithium insertion and the interaction between Li and the Si electrode must be understood at the atomic level; this understanding can be achieved by first-principles simulation. Here, first-principles computations of lithiation in silicon electrodes are reviewed. The review focuses on three aspects: the various properties of bulk Li-Si compounds with different Li concentrations, the electronic structure of Si nanowires and Li insertion behavior in Si nanowires, and the dynamic lithiation process at the Li/Si interface. Potential study directions in this research field and difficulties that the field still faces are discussed at the end. 1. Introduction Energy storage is a crucial aspect of integrating renewable energy sources in power grids, which makes the development of efficient high-capacity batteries an important technological field [1]. Li ion batteries have been the most important portable power source for consumer electronics and show great promise for vehicle electrification.